Note:
Unlike many other mechanisms in PHP, variables stored using
apcu_add() will persist between requests (until the
value is removed from the cache).

Parameters

key

Store the variable using this name. keys are
cache-unique, so attempting to use apcu_add() to
store data with a key that already exists will not overwrite the
existing data, and will instead return FALSE. (This is the only
difference between apcu_add() and
apcu_store().)

var

The variable to store

ttl

Time To Live; store var in the cache for
ttl seconds. After the
ttl has passed, the stored variable will be
expunged from the cache (on the next request). If no ttl
is supplied (or if the ttl is
0), the value will persist until it is removed from
the cache manually, or otherwise fails to exist in the cache (clear,
restart, etc.).

values

Names in key, variables in value.

Return Values

Returns TRUE if something has effectively been added into the cache, FALSE otherwise.
Second syntax returns array with error keys.